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Commit e3d06ff9 authored by Sunil Goutham's avatar Sunil Goutham Committed by David S. Miller
Browse files

net: thunderx: Support for XDP header adjustment 



When in XDP mode reserve XDP_PACKET_HEADROOM bytes at the start
of receive buffer for XDP program to modify headers and adjust
packet start. Additional code changes done to handle such packets.

Signed-off-by: default avatarSunil Goutham <sgoutham@cavium.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 16f2bccd

drivers/net/ethernet/cavium/thunder/nicvf_main.c

+47 −16
Original line number Diff line number Diff line
@@ -502,13 +502,15 @@ static int nicvf_init_resources(struct nicvf *nic) 
}



static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog,

				struct cqe_rx_t *cqe_rx, struct snd_queue *sq)

				struct cqe_rx_t *cqe_rx, struct snd_queue *sq,

				struct sk_buff **skb)

{

	struct xdp_buff xdp;

	struct page *page;

	u32 action;

	u16 len;

	u16 len, offset = 0;

	u64 dma_addr, cpu_addr;

	void *orig_data;



	/* Retrieve packet buffer's DMA address and length */

	len = *((u16 *)((void *)cqe_rx + (3 * sizeof(u64))));
@@ -517,17 +519,47 @@ static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog, 
	cpu_addr = nicvf_iova_to_phys(nic, dma_addr);

	if (!cpu_addr)

		return false;

	cpu_addr = (u64)phys_to_virt(cpu_addr);

	page = virt_to_page((void *)cpu_addr);



	xdp.data = phys_to_virt(cpu_addr);

	xdp.data_hard_start = page_address(page);

	xdp.data = (void *)cpu_addr;

	xdp.data_end = xdp.data + len;

	orig_data = xdp.data;



	rcu_read_lock();

	action = bpf_prog_run_xdp(prog, &xdp);

	rcu_read_unlock();



	/* Check if XDP program has changed headers */

	if (orig_data != xdp.data) {

		len = xdp.data_end - xdp.data;

		offset = orig_data - xdp.data;

		dma_addr -= offset;

	}



	switch (action) {

	case XDP_PASS:

		/* Pass on packet to network stack */

		/* Check if it's a recycled page, if not

		 * unmap the DMA mapping.

		 *

		 * Recycled page holds an extra reference.

		 */

		if (page_ref_count(page) == 1) {

			dma_addr &= PAGE_MASK;

			dma_unmap_page_attrs(&nic->pdev->dev, dma_addr,

					     RCV_FRAG_LEN + XDP_PACKET_HEADROOM,

					     DMA_FROM_DEVICE,

					     DMA_ATTR_SKIP_CPU_SYNC);

		}



		/* Build SKB and pass on packet to network stack */

		*skb = build_skb(xdp.data,

				 RCV_FRAG_LEN - cqe_rx->align_pad + offset);

		if (!*skb)

			put_page(page);

		else

			skb_put(*skb, len);

		return false;

	case XDP_TX:

		nicvf_xdp_sq_append_pkt(nic, sq, (u64)xdp.data, dma_addr, len);
@@ -537,7 +569,6 @@ static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog, 
	case XDP_ABORTED:

		trace_xdp_exception(nic->netdev, prog, action);

	case XDP_DROP:

		page = virt_to_page(xdp.data);

		/* Check if it's a recycled page, if not

		 * unmap the DMA mapping.

		 *
@@ -546,7 +577,8 @@ static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog, 
		if (page_ref_count(page) == 1) {

			dma_addr &= PAGE_MASK;

			dma_unmap_page_attrs(&nic->pdev->dev, dma_addr,

					     RCV_FRAG_LEN, DMA_FROM_DEVICE,

					     RCV_FRAG_LEN + XDP_PACKET_HEADROOM,

					     DMA_FROM_DEVICE,

					     DMA_ATTR_SKIP_CPU_SYNC);

		}

		put_page(page);
@@ -654,7 +686,7 @@ static void nicvf_rcv_pkt_handler(struct net_device *netdev, 
				  struct napi_struct *napi,

				  struct cqe_rx_t *cqe_rx, struct snd_queue *sq)

{

	struct sk_buff *skb;

	struct sk_buff *skb = NULL;

	struct nicvf *nic = netdev_priv(netdev);

	struct nicvf *snic = nic;

	int err = 0;
@@ -676,15 +708,17 @@ static void nicvf_rcv_pkt_handler(struct net_device *netdev, 
	}



	/* For XDP, ignore pkts spanning multiple pages */

	if (nic->xdp_prog && (cqe_rx->rb_cnt == 1))

		if (nicvf_xdp_rx(snic, nic->xdp_prog, cqe_rx, sq))

	if (nic->xdp_prog && (cqe_rx->rb_cnt == 1)) {

		/* Packet consumed by XDP */

		if (nicvf_xdp_rx(snic, nic->xdp_prog, cqe_rx, sq, &skb))

			return;

	} else {

		skb = nicvf_get_rcv_skb(snic, cqe_rx,

					nic->xdp_prog ? true : false);

	}



	skb = nicvf_get_rcv_skb(snic, cqe_rx, nic->xdp_prog ? true : false);

	if (!skb) {

		netdev_dbg(nic->netdev, "Packet not received\n");

	if (!skb)

		return;

	}



	if (netif_msg_pktdata(nic)) {

		netdev_info(nic->netdev, "%s: skb 0x%p, len=%d\n", netdev->name,
@@ -1672,9 +1706,6 @@ static int nicvf_xdp_setup(struct nicvf *nic, struct bpf_prog *prog) 
		return -EOPNOTSUPP;

	}



	if (prog && prog->xdp_adjust_head)

		return -EOPNOTSUPP;



	/* ALL SQs attached to CQs i.e same as RQs, are treated as

	 * XDP Tx queues and more Tx queues are allocated for

	 * network stack to send pkts out.

drivers/net/ethernet/cavium/thunder/nicvf_queues.c

+8 −1
Original line number Diff line number Diff line
@@ -164,6 +164,11 @@ static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, struct rbdr *rbdr, 
	}



	nic->rb_page_offset = 0;



	/* Reserve space for header modifications by BPF program */

	if (rbdr->is_xdp)

		buf_len += XDP_PACKET_HEADROOM;



	/* Check if it's recycled */

	if (pgcache)

		nic->rb_page = pgcache->page;
@@ -183,7 +188,7 @@ static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, struct rbdr *rbdr, 
			return -ENOMEM;

		}

		if (pgcache)

			pgcache->dma_addr = *rbuf;

			pgcache->dma_addr = *rbuf + XDP_PACKET_HEADROOM;

		nic->rb_page_offset += buf_len;

	}
@@ -1575,6 +1580,8 @@ static void nicvf_unmap_rcv_buffer(struct nicvf *nic, u64 dma_addr, 
		 */

		if (page_ref_count(page) != 1)

			return;



		len += XDP_PACKET_HEADROOM;

		/* Receive buffers in XDP mode are mapped from page start */

		dma_addr &= PAGE_MASK;

	}